Marsiiyohranchs of the Order Hyperoartii. 195 



Synopsis of the Species. 



I. Enlarged cusps of anterior lingual lamina small, the denticulated 



ridge evident. 



The two most anterior of the radial series of labial teeth 

 meet behind and, diverging in front, are separated by 

 a single tooth _ 1. lapicida. 



The two most anterior of the radial series of labial teeth 



are entirely separated by a group of three teeth .... 2. mordax. 



II. Enlarged cusps of anterior lingual lamina very strong, hiding the 



denticulated ridges 3. acutidens. 



1. Mordacia lapicida, 



Caragola lapicida, Grav, Ohondropt. p. 143, pi. i. fig. 5 (1851), or Proc. 



Zool. Soc. 1851, p. 239. 

 Mordacia morda.c (part), Giinth. Cat. Fish. viii. p. 507 (1870). 

 Mordacia lapicida, Plate, Zool. Jahrb. Suppl. v. 1902, p. 656, pi. xix. 



figs. 3-4. 



Chile. 

 L 160 mm. (type of the species). Valparaiso. 



2. Mordacia mordax. 



Petroimjzon mordax, Richards. Ei-eb. & Terr. Fish. p. 62, pi. xxxviii. 



figs. 3-6 (1848). 

 Mordacia mordax, Gray, Chondropt. p. 144, pi. i. fig. 6 (1851), or 



Proc. Zool. Soc. 1851, p. 239, pi. iv. tig. 6 ; Ogilb. Proc. Linn. Soc. 



N.S.W, xxi. 1896, p. 400; Plate, Zool. Jahrb. Suppl. v. 1902, 



p. 654, pi. xix. figs. 1-2. 

 Mordacia mordax (part.), Giinth. Cat. Fish. viii. p. 507 (1870). 



New South Wales ; Victoria ; Tasmania. 



1. 250 mm. (type of the species). Tasmania. Ha^jlar Coll. 



2. 330 mm. „ M. Allport, Esq. 



3. Mordacia acutidens. 



? Petromyzon amvandteri, Pbilippi, Arch. f. Nat. 1803, p. 207, pi. x. 



fig.i. 

 Petromyzon acutidens, Philippi, ib. 1864, p. 107, or Ann. & Mag. Nat. 



Hist. xvi. 1865, p. 221. 

 Mordacia acutidens, Plate, Zool. Jahrb. Suppl. v. 1902, p. 657, pi. xix. 



figs. 5-6. 



Chile. 

 1-2. 320-330 mm. Chile. Gerrard. 



13* 



